1. Field of the Invention
The present invention relates to a seat rail apparatus for a vehicle, and more particularly to a seat rail apparatus for a vehicle having a walk-in memory function by which a seat can return to a position adjusted before when the seat is moved through a walk-in operation to return to an original position in a state in which the seat is adjusted to an optimum position by a passenger to correspond to the body shape of the passenger.
2. Description of Related Art
In general, a vehicle seat includes a seat cushion for supporting the hip of a user, and a seat back for supporting a back, and has various functions for convenience of a user.
For example, a user (a driver or a passenger) can push or pull a seat cushion forwards and rearwards in correspondence to his or her body shape to adjust a position of the seat cushion, and can also rotate a seat back with respect to the seat cushion by a predetermined angle.
Thereto, a vehicle seat includes a seat rail apparatus for moving an entire seat forwards and rearwards such that a position of the seat can be adjusted in correspondence to the body shape of a user, and further includes a folding apparatus for folding a seat back forwards, and a recliner apparatus for adjusting an angle of the seat back.
Here, the seat rail apparatus includes a seat track (a combination of an upper rail and a lower rail) installed between a cushion frame and a vehicle floor to move the seat forwards and rearwards, and a locking unit for locking and unlocking the upper rail mounted to the cushion frame to and from the lower rail mounted to the vehicle floor according to a manipulation of a track lever.
A walk-in seat including a walk-in function by which a seat can be moved forwards and then moved rearwards in a seat back folding state for a ride of a passenger of a back seat may be installed according to a model of a vehicle.
The walk-in function is a function for sliding a front seat forwards by using a recliner apparatus and a seat rail apparatus to help a ride of a passenger of a back seat or maximize expansion of a space, and is a function for moving an entire seat forwards while a locking unit is unlocked in conjunction with the recliner apparatus if a front seat back is folded to allow a passenger to ride a back seat or get off from the back seat.
FIGS. 1 and 2 are side views illustrating a walk-in function of a vehicle seat. An operation lever 9 (having different positions and shapes according to models of vehicles) is provided at one side of a walk-in seat to perform a walk-in function. If the operation lever 9 is manipulated, a recliner apparatus of a seat back is operated while a cable is operated in conjunction with a link and then the seat back 10 is folded forwards.
A walk-in cable is pulled further in conjunction with an operation of the recliner apparatus while the seat back 10 is folded forwards, and if the walk-in cable is pulled, a locking unit of a seat rail apparatus unlocks a lower rail to perform a walk-in operation by which the seat is slid forwards.
Meanwhile, during a walk-in return, that is, when the seat returns to a position where a user can be seated, the folded seat back is unfolded backwards when a forward and rearward position of the seat is made suitable by pushing back the seat such that a position of the seat is fixed by the locking unit.
That is, the seat back folded after the seat is moved rearwards is unfolded, an upper rail of a cushion frame is automatically locked with a lower rail of a vehicle floor by a locking unit such that a position of the seat can be fixed in its place.
However, in a conventional walk-in seat, during a walk-in return of a passenger, a seat should be moved backwards to a predetermined position (for example, a rearmost position) to be stopped, and then a position of the seat should be adjusted again in correspondence to the body shape of the passenger.
In particular, if a walk-in operation is performed while a passenger adjusts a seat to an optimum position in correspondence to the body shape of the passenger, the passenger should adjust the position of the seat to an optimum position again after being seated on the seat after walk-in return.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.